1. Field of the Invention
This invention relates generally to apparatus for magnetic separation of substances, and more particularly concerns an apparatus for separating ferromagnetic materials from fluid media.
2. Description of the Related Art
There is known an apparatus for separating ferromagnetic materials from fluid media comprising one stationary working passage filled with an insert of ferromagnetic material and having an inlet pipe for feeding a fluid medium to be cleaned and an outlet pipe for discharging the clean fluid medium, and a magnetizing system in the form of a solenoid arranged outside the passage coaxially therewith to magnetize the ferromagnetic insert (DE,C, 1,277,488).
This apparatus is inherently disadvantageous due to that it fails to provide a continuous process of fine magnetic cleaning. During regeneration of the ferromagnetic filtering insert the fluid medium is temporarily conveyed along a by-pass pipe without cleaning. When cleaning highly contaminated media, such as circulating water in metallurgy, the operation period between regenerations amounts to only several hours. In such a case the overall efficiency of the cleaning process is determined by including the time required for regeneration, when the fluid medium is conveyed along the by-pass pipe.
There is also known an apparatus for separating ferromagnetic materials from fluid media comprising at least one stationary working passage divided by a hermetic partition into two successive sections each filled with an insert of ferromagnetic material and having an inlet pipe for feeding a fluid medium to be cleaned to the section and an outlet pipe for discharging the clean fluid medium, and a magnetizing system disposed outside the passage to magnetize the ferromagnetic insert of one such section and provided with a means for imparting thereto a reciprocating movement along the passage between two extreme positions, viz., at the first section and at the second section (cf., U.S. Pat. No. 4,602,997).
In this prior art apparatus the means for imparting reciprocating movement is fashioned as an intricate electromechanical construction including an electric motor, a reducing gear, a worm-and-worm gear, and rods for attaching the magnetizing system to the worm gear. Apart from these principle elements, the reciprocating means includes a system for lubricating the reducing and worm gear pairs, and a large-size base for accommodating parts and elements. Provision of auxiliary elements still further complicates the apparatus structurally. In addition, the reciprocating means includes electromagnets energizable for producing a magnetic cushion when stopping the magnetizing system.
The up and down travel of the magnetizing system effected by the electric motor and worm-and-worm gear is a relatively slow procedure taking a time space of several minutes. During such a procedure the electric drive consumes electric power, and the contaminated fluid medium is either drained or returned to the process flow line thereby reducing the overall efficiency of the process and making the process of cleaning more expensive.